Hydraulic pump and motor power system



Jan- 27, 1953 DE Loss D. WALLACE ErAL 2,626,503

HYDRAULIC PUMP AND MOTOR POWER SYSTEM Filed July 25, 1951 IN VEN TORS 0.61055 0. Mamas fir/0 Y Wann/1 F Eem/(50N Patented Jan. 27, 1953 HYDRAULIC PUMP AND MOTOR POWER SYSTEM De Loss D. Wallace and William F. Erickson, Dayton, Ohio, assignors to General Motors. Corporation, Detroit, Mich., ay corporation of Dela- Application July 25, 1951, SerialNo. 238,562

8 Claims.

This invention relates to a hydraulic power system including a fluid pressure pump and a fluid actuated motor.

Some automobiles are equipped with hydraulically actuated mechanism for raising and lowering the windows and the top of the vehicle. The actual raising and lowering operation, especially with the windows, is performed by a fluid motor operated in one direction by fluid pressure and in the opposite direction by a spring. A fluid pressure pump, communicating with a fluid reservoir, provides the fluid pressure to actuate the motor. In some installations a separate motive power is used to drive the pump and in others, the electric starting motor, primarily used to start the engine of the vehicle, has the pump connected thereto so as to be driven thereby. In the latter instance the pump is actuated whenever the starting motor operates and conh sequently it is necessary to provide arrangements so that the pump may be operated idly or without deivering fluid pressure to the fluid motor while the electric motor acts to start the engine and so that the electric motor may be actuated to drive the pump for window actuating purposes without the engine beingr cranked by said electric motor.

It is therefore among the objects of the present invention to provide a fluid pressure pump with a control device which, when the electric motor is energized to crank the engine and at the same time drive the pump, will set up iluid circuits permitting the fluid delivered by the pump to be idly circulated between the pumpA and reservoir thereby relieving'fluid pressure.

A further object of the present invention is to provide a control device for a fluid pump, which, when said pump is being driven by the electric motor free of the engine, sets up fluid flow circuits through which fluid under pressure from the pump is delivered to the fluid motor for actuating it.

A still further object of the present invention is to provide the control device with mechanism cooperating to set up fluid circuits again to establish-idling'uid circulation between the pump and fluid reservoir in response to an excess of fluid pressure beyond a predetermined operating degree.

Further objects and advantages of the present inventionv will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is a diagrammatic View primarily illustrating the electrical circuits of anV installation utilizing the present invention.

F.' g. 2 is a transverse sectional View taken substantially along the line and in the direction of the arrows 2 2 in Fig. 4.

Fig. 3 is a side view of the unitary mechanism providing the pump, the reservoir and the fluid flow control device of thepresent invention. The view is taken in the direction of the arrow 3 appearing in Fig. 4.

Fig. 4 is a view of the unitary mechanism shown in Fig. 3, taken, however, from another side thereof.

Fig. 5 is a fragmentary sectional View of elements of the control mechanism in a position differing from that shown in Fig. 2.

Fig. 6 is a view similar to Fig 5, the elements being shown in a still different position, however.

Referring to the drawing, Fig. l showselectrical devices and circuits used'to operate the motor 26 for cranking the engine, only a portion of its flywheel 2| being illustrated. The motor 20 has a rotatable shaft 22 upon which a pinion 23 is shiftably keyed so as to be movable to mesh with teeth on the flywheel 2|. The pivoted lever 24 shfts the pinion 23 on shaft 22. Lever 24 is actuated by an armature 25 movable longitudinally by a magnet winding 25 and held so that the bridging contact 21 engages stationary terminals 28 and 29, by a holding magnet winding 30. One end of magnet winding 26 and terminal 29 are connected to one endV of the motor field winding 3| also connected to the motor brush 32. The other end of winding 26 as well as one end of winding 30 are connected to terminal 33 ofthe motor starting switch 34. The other end of winding 30 is connected to terminal 35 of switchV 34. The terminal 35, connectible with terminal 33 by the bridging element 31 of switch 34', isY connected to one side of the battery 38 asis the terminal 28. Terminal 39 of switch 34, connectible withterminal 35 by the bridging element 40, is grounded the same. as the other side of the battery and the other brush 4|. of the motor 20. Thus when switch 34 is operated to connect terminal. 33 to 36 and 35 to 39 by bridging elements 31 and. 40 respectively, the magnet windings 26 and 35 and the motor winding 3| are energized. In response armature 25 is shifted longitudinally to connect terminals 2B and 29 by bridging contact 21 directly to connect the battery with the. motor windng3| lto render the/motor` operativei while yshifting of the armature 25 actuates lever 24. to

shift pinion 23, now being rotated, into mesh with the flywheel 2| to start the engine.

The fluid pump 50 is driven by the electric motor 20 whenever it is operated. Said pump has a uid inlet port 5| connected to the fluid reservoir 52 and a fluid discharge port 53 connected to the opening 54 of the uid flow control device 55. Another opening 56 provided in the fluid flow control device is connectible to the fluid motor 51, shown in Fig. 1. This fluid motor is illustrated as of the cylinder-piston type, consisting of a cylinder 58 in which a piston 59 is reciprocative. Any suitable control valve 60 is provided in the line connecting one end of cylinder 58 With the fluid discharge opening 56 of the control device 55 and is operative to connect and disconnect said cylinder and discharge port. A spring 6| yieldably urges the piston 59 toward the end of the cylinder 58 into which fluid is introduced.

Control valve 60 is manually operated by a lever which also actuates a switch at the same time. This switch consists of a movable lcontactor 65 electrically connected to the motor field winding 3| and a stationary terminal 66 connected to the battery 38 and engageable by said contactor to close the circuit between the battery and motor eld and thus render the motor active without causing the pinion 23 to be shifted into meshing engagement with the engine flywheel. When the switch is actuated from normal into terminal 66 engaging position, valve 68 is opened at the same time to connect the fluid motor cylinder 58 with the fluid pressure opening 56 so that fluid pressure in said cylinder moves the piston 59 against the effect of spring 6|. Moving switch contactor 65 back to normal pcsition as shown in Fig. 1, breaks the motor circuit and renders the motor inoperative and at the same time discontinues communication between the motor cylinder 58 and fluid discharge opening 56. Now fluid is trapped in cylinder 58 'and thus piston 59 is held immovable therein. When the switch contactor 65 is moved from normal into the position 61, Fig. 1, then no electrical circuit is completed, however, the valve 60 is again actuated to complete communication between cylinder 58 and the discharge opening 56 so that the spring 6| may now move piston 59 to eject fluid from cylinder 58 through opening 55 into the reservoir 52.

The feature of this invention is the unitary control mechanism for establishing fluid flows between the fluid reservoir, pump and fluid cylinder so as to permit proper operation of the hydraulic system for actuating window lifting mechanism in the desired manner. This control mechanism is contained within a single housing 'l0 provided with an end cover 1|. A plurality of interconnected fluid flow passages and spaces are provided within the housing 10. One passage communicates at one end with a cylindrical passage or recess 16, the other end of passage 15 opening into an enlarged annular recess 11 into which a smaller diameter, annular core 18 extends. This recess l1 provides a container for the magnet winding 80 one end of which is grounded to the housing, the other end being connectible to the line leading from switch contactor 65 to the motor eld 3| s0 that when switch contacter is moved into engagement with terminal 86 to complete the circuit between the battery 38 and the motor field 3|, magnet winding 80 will also be brought into circuit connection with the battery. Core 18 extends into the `4 magnet winding and forms the magnetic core therefor. The passage l5 terminating in the end surface of the core 18 is counterbored to receive the annular valve seat 19. The cover 1| is interiorly shaped to form a space 8| providing communication between the valve seat 19 and the cylindrical recess 16.

A round, magnetic plug with longitudinal grooves 86 in its peripheral surface is slidably supported in a sleeve fitted within the magnet winding 80 and forms the movable armature for said magnet winding. This plug supports a non-magnetic stem 8l coaxially thereof, the inner end of said stem being tapered and forming a valve movable into engagement with the seat 19 to shut off communication between passage 15 and the space 8| under certain circumstances. Communicating with passage i5 is the opening 54 in the housing which, as has been said, is in communication with the pump discharge port 53. An opening 88 shown in Figs. 1, 5 and 6 and opening 56, spaced from opening 88, lead from the recess 16 to the reservoir 52 and fluid motor cylinder 58 respectively. The reservoir 52, in the form of a can, is secured and sealed upon a disc like flange 89 formed on the housing l0. A pipe 90 extends into the reservoir and is connectible with the intake port 5| of the pump 50 so that said pump may withdraw lfluid from said reservoir. A similar pipe 9| extends into the reservoir and communicates with the opening 88.

At the end of recess 16 opening into the space 8| there is inserted a cylindrical sleeve 95 forming the cylinder in which the piston 96 provided with suitable venting orifices reciprocates. This piston has a stem 91 extending coaxially therefrom' which is slidably supported in a centrally apertured collar 98 held between the inner end of sleeve 85 and a shoulder in recess 16. Washers 99 are carried by stem 9'! and form an adjustable abutment for one end of spring |00. The other end of spring |00 engages the sleeve member |0|, forming one part of the two-way acting control valve in recess 16, and yieldably holds said sleeve |0| against a shoulder at this end of the recess. Sleeve 0| has an inwardly extending annular flange |02 forming a seat for the ball |63, another member of the two-way valve. Movement of the ball from seat |02 is normally limited by the shoulder in the housing at the point of juncture of recess 'I6 with passage 15.

When the motor 20 is activated tovcrank the engine motor, pump 50 is also driven and thus will draw fluid from the reservoir and deliver it under pressure through opening 54 in the control device 55 into passage 15. Inasmuch as the fluid motor control valve has not been opened in this instance, the fluid pressure flow into passage 'l5 cannot be delivered to said fluid motor and thus must be directed in another direction inasmuch Aas it is stopped by valve IUI-|03. Fluid pressure in passage 'l5 under these circumstances is directed through the valve seat 19 against valve 81 and will move the valve 81 and its supporting armature block 85 into the position as shown in Fig. 2 in which fluid flows from seat 19 through the longitudinal grooves 86 in the varmature block 85 into space 8| to be directed against the piston 96. In response to the fluid pressure against the piston 96 said piston and its stem 91 will be moved so that stem 91 will approach and engage ball |03 to move it from its annular seat |0| in the sleeve portion |02 of this valve mechanism and thereby open an escape passages through said sleeve portionofL the valve int'o the recess 161 and from there into the opening 88 connected with the reservoir 52 by pipe 9i. Fig. 5 shows the mechanism in this control position. Fluid will not now through opening 515 inasmuch as valve 6ft is closed at this time. Thus, while the pump is being driven bythe electric motor 20 acting as an engine cranking device, iiuid delivered under pressure by the pump is directed against piston 96 to move it into and'hold it inthe sleeve |92 opening position vas shown in Fig. 5, the fluid under pressure is suiiicient for being circulated from the pump, through passage 15, valve m2, recess 16, opening 88 and pipe 9i back to the reservoir from which the iuid was fl'rst'd'rawn by the pump. l

When the'- el'ectric motor il is to be operated for window adjustment purposes only and notas an' engine cranking' medium, switchA contactor 65 is actuated to engage terminal 66 atthe same time valve IBil is opened to complete communication between the outlet 56 and the fluid motor cylinder B. Now the motor 2t is activated to drive the pump only and the magnet'winding 89 is connected in circuit with the battery to be energized thereby. The energized magnet winding Bil will cause the armature block 85 to move inwardly so that the valve 81 in said block will engage and close the seat 1S, thereby shutting off communication between the pump iiuid pressure passage andthe space 3l to which piston 95 is exposed. Fluid pressure in passage i5 is now directed against and moves valves idS-ll as -a unit toward stem Si and thus normally positions said stem ill and its vented piston 96 in recess ?5 and as the sleeve i532 moves in said recess it will open communication between passage 15 and opening 5S to direct the fluid pressure throughthe now open valve Bil to the fluid motor cylinder 53, said fluid pressure forcing the piston 59. from its position in the cylinder toward the opposite end of said cylinder against the opposition by spring Si, The piston, beingv connected by its rod and rassociated levers, not shown, with the vehicle window to be operated, will by its movement by fluid pressure adjust said window. When the desired adjustment of the window is completed, valve Si! `and contactor B5 are again actuated to close communication between the pump and fluid motor and to break the circuit to the electric motor 2G and the electromagnet winding 8F, thereby rendering said electric motor inoperative to stop pump'operation and to deen'ergize the winding to. The huid motor willbe held in the adjusted position due to ofthe fluid therein by the closing of valve 5u.

In case of excessive pressure in passage 'l5 or when the pump operation is maintained yafter the iiuid motor piston 59 has been moved into its eX- treme pressure actuated position, valve lill-HB3 will be moved as a unit further into recess 16 until the ball H33 pushes the stem 91 and its piston into the extreme normal position thereby halting its further movement in this direction as shown in Fig. 6. The fluid pressure will, however continue to move the sleeve 10| relatively to the stalled ball H33, thereby moving the seat 102 away from the ball and thus opening an escape passage for the duid through sleeve IBI intorecess 'i6 and through opening 88 and pipe Si into the reservoir. This relieves the excessive fluid pressure and thus avoids possible damage thereby. l While the embodiment of the present invention as herein disclosed, constitutes a preferred the trapping form, itl is toi bef understood. that:` othertorms might be-vadopted.

Wh'atis ciaimedis as follows:

I. A fluid flowA control device'r consisting of. a housinginwhich isprovided a passagewith which a` fluid pressure discharge port oa-pump, aconnectionwith al fluid reservoir and a connection with a fluid actuated motor all communicate; double acting valvemeans in said passage normally shutting off' communication between the pump port and both the motor and fluid reservoir; actuator means in the passage operative out of normal position by fluid pressure to engage and actuate the double acting valve means for opening communication between the pump port and the reservoir;` a normally open control valve in' the passage between the pumpv port and said actuator means, said control valve being operative out ofy normal position to shut off` communication between the pump port' and said actuator means rendering it inactive, at which time fluid pressure from the pump port' is directed against and actuate's said double acting valve means concurrentiyr to open communication between the pump port and the motor and to close the passage to shut on" communication between the reservoir and the motor; and'means lin the housing for actuating the control valve.

2. A device in accordance with claim l, in'which the double acting valve means is' movable, by excessive fluid pressure from the pump port, to engage the actuator means and be operated thereby for connecting the pump port with the reservoir.

3. A fluid flow control device connected to a fluid reservoir, a nuid pressure pump and a' iiuid actuated motor, said device consisting of a housing providing interconnected iiuid flow passages in communication with the reservoir, pump and motor; a check valve in one of the passages normally shutting off communication between the pump pressure passage and both the reservoir and motor and maintaining communication between the motor and reservoir; means in said check valve passage, operative by iiuid pressure to engage and actuate said check valve for opening communication between the pump pressure passage and said reservoir; a control valve in another' passage, normally maintaining said passageopen to provide communication between the pump pressure passage and said means; and an electromagnet in said housing, operative, when energized, to close said control valve to discontinue the communication betweenthe pump pressure passage and said means, whereby the check valve is actuated by fluid pressure in said pump pressure passage to connect the pump pressure with the motor and to disconnect the pump pressure from the reservoir.

4. A iiuid flow control device adapted to be connected to a fluid reservoir, a fluid pressure pump and a fluid actuated motor, said device consisting of a housing providing interconnected fluid flow passages one of which is a pump pressure passage communicating with the pressure side of the pump and another of which communicates with both the iiuid reservoir and the fluid motor; a normally closed two way valve normally shutting oir communication between the pump pressure passage and the said other passage; pressure operative means in said other passage engageable with the two Way valve for actuating it one way to open communication between the pump pressure passage and the reservoir; a control valve normally open to complete communication between the pump pressure passage and the pressure operative means; and an electromagnet operative to close said control valve whereby fluid pressure in said pump pressure passage actuates the two way valve the other way to open communication between the pump pressure passage and the motor and to close communication between the motor and the reservoir.

5. A fluid flow control device connected to a fluid reservoir, to a fluid pressure pump and to a fluid pressure actuated motor, respectively, said device consisting of a housing providing interconnected passages one of which forms a pump pressure passage, with which the fluid motor and a discharge pipe to the reservoir communicate; a two-way check valve in one of the passages, normally shutting off communication between the pump pressure passage and the fluid motor and maintaining communication between said motor and the discharge pipe to the reservoir; means in said one of the passages, normally subjected to Vfluid pump pressure and operative thereby to en- A gage and actuate the two-way valve in one direction for opening communication between the pump pressure passage and the reservoir discharge pipe; a normally open shut-01T valve between the pump pressure passage and said means; an electromagnetic coil in the housing operative, when energized, to close the shut-off valve whereby communication between the pump pressure passage and said means is discontinued and fluid pressure actuates the two-way valve in the other direction for establishing communication between the pump pressure passage and the fluid motor and discontinuing communication between the said motor and the reservoir discharge pipes.

6. A device in accordance with claim 4 in which the two-way check valve is movable into engagement with the said pressure operative means and operated thereby to open communication between the pump pressure passage and the reservoir discharge pipe in response to a predetermined excessive iluid pressure in the pump pressure passage.

7. A fluid ow control device consisting of a housing having a cylindrical recess with which pipe connections from a fluid reservoir and from a fluid actuated motor communicate, a passage communicating with one end of said recess, the discharge pipe of a fluid pressure pump being connected with said passage, and a space providlng communication between the said passage and the other end of the cylindrical recess; a twoway check valve in the recess, said check valve consisting of a sleeve slidable in the recess and providing an inner, annular seat engaged by a ball to close the sleeve; a vented piston slidable in said cylindrical recess, said piston having a stem extending toward the two-way check valve; a spring engaging the check valve sleeve and normally urging it against a stop at one end of said cylindrical recess, the communicating openings to the reservoir and pump coming between the normally positioned piston and said two-way check valve; an armature in said space, carrying a Valve operative by the armature to shut oil' communication between the said passage and the space; and an electromagnet coil in said space operative, when energized, to actuate the armature for closing said passage.

8. A fluid flow control device connected to a uid reservoir, to a fluid pressure pump and a fluid actuated motor, said device consisting of a Vunitary housing providing interconnected iiuid passages in communication with the reservoir, pump and motor; a compound check valve in one of the passages normally shutting off communication between the pump and the motor and reservoir while maintaining communication between the said motor and reservoir; means in said one passage operative by fluid pressure to engage and adjust said compound check valve for opening communication between the pump and fluid reservoir; a control valve normally maintaining communication between the pump and said means for rendering said means operative by fluid pressure; an electromagnet in the housing operative, when energized, to move the control valve to shut off communication between the pump and said means, in response to which fluid pressure from the pump actuates the nrst mentioned check valve to open communication between the pump and motor and close communication between the pump and fluid reservoir, said compound check valve being operative by a predetermined increase in pump fluid pressure to engage said means and be adjusted thereby to open communication between the pump and the reservoir.

DE LOSS D. WALLACE. WILLIAM F. ERICKSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,139,473 Sessions Dec. 6, 1938 2,425,391 Parsons Aug. 12, 1947 

